Prostate Cancer Causes, Signs, Symptoms, Diagnosis, Treatment, Prevention

Prostate Cancer Causes, Signs, Symptoms, Diagnosis, Treatment, Prevention


The Prostate


The prostate is a gland in a man's reproductive system. It makes and stores seminal fluid, a milky fluid that nourishes sperm. This fluid is released to form part of semen.

The prostate is about the size of a walnut. It is located below the bladder and in front of the rectum. It surrounds the upper part of the urethra, the tube that empties urine from the bladder. If the prostate grows too large, the flow of urine can be slowed or stopped.

To work properly, the prostate needs male hormones (androgens). Male hormones are responsible for male sex characteristics. The main male hormone is testosterone, which is made mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands.

What Is Prostate Cancer?


The prostate is a gland in the male reproductive system. It makes most of the semen that carries sperm. The walnut-sized gland is located beneath the bladder and surrounds the upper part of the urethra, the tube that carries urine from the bladder.

Prostate cancer is a major health concern for American men. The disease is rare before age 50, and experts believe that most elderly men have traces of it.

In 2013, about 238,500 new cases will be diagnosed in the U.S., and about 29,700 will die of it. African-American men are more likely to get prostate cancer and have the highest death rate. In other parts of the world - notably Asia, Africa, and Latin America - prostate cancer is rare.

Prostate cancer is usually a very slow growing cancer, often causing no symptoms until it is in an advanced stage. Most men with prostate cancer die of other causes, and many never know that they have the disease. But once prostate cancer begins to grow quickly or spreads outside the prostate, it is dangerous.

Prostate cancer in its early stages (when it’s only found in the prostate gland) can be treated with very good chances for survival. Fortunately, about 85% of American men with prostate cancer are diagnosed in an early stage of the disease.

Cancer that has spread beyond the prostate (such as to the bones, lymph nodes, and lungs) is not curable, but it may be controlled for many years. Because of the many advances in available treatments, most men whose prostate cancer becomes widespread can expect to live five years or more. Some men with advanced prostate cancer live a normal life and die of another cause, such as heart disease.

Prostate Cancer Causes


The specific cause of prostate cancer remains unknown. Hormonal, genetic, environmental, and dietary factors are thought to play roles. Yet, the only well-established risk factors for prostate cancer are age, ethnicity, and heredity.

Age


There is a strong correlation between increasing age and developing prostate cancer. The incidence of prostate cancer increases steadily from less than 1 in 100,000 for men 40 years of age to 1,146 per 100,000 in men 85 years of age. The median age at diagnosis of prostate cancer is 70.5 years of age. More than 80% of prostate cancers are diagnosed in men older than 65 years of age. Autopsy records indicate that 70% of men older than 90 years of age have at least one region of cancer in their prostate.

Ethnic origin


In the U.S., African American men are 1.6 times more likely than Caucasian men to develop prostate cancer. They are also 2.4 times more likely to die from their disease as compared to Caucasian men of a similar age. Asian Americans, on the other hand, have a much lower chance of getting prostate cancer as compared to Caucasians or African Americans. Internationally, Caucasian men from Scandinavian countries experience the highest rates whereas men from Asia the lowest. Although, these ethnic criteria have been used to study and describe the disease in the past, there is no defined biologic basis for this classification. In other words, these differences in diagnosis and death rates are more likely to reflect a difference in factors like environmental exposure, diet, lifestyle, and health-seeking behavior rather than racial susceptibility to prostate cancer. Recent evidence, however, suggests that this disparity is progressively decreasing with high chances of complete cure in men undergoing treatment for organ-confined prostate cancer (cancer that is limited to within the prostate without spread outside the confines of the prostate gland) irrespective of race.

Family history


Men who have a history of prostate cancer in their family, especially if it is a first-degree relative such as a father or brother, are at an increased risk of developing prostate cancer. If one first-degree relative has prostate cancer, the risk is at least doubled. If two or more first-degree relatives are affected, the risk increases by 5- to 11-fold.

Diet


Dietary factors may influence the risk of developing prostate cancer. Specifically, total energy intake (as reflected by body mass index) and dietary fat have been incriminated. In addition, there is some evidence that suggests that obesity leads to an increased risk of having a more aggressive, larger prostate cancer, which results in a poorer outcome after treatment. Nevertheless, the question remains whether there is enough evidence to recommend lifestyle changes specifically to prevent prostate cancer independently of the known health and cardiovascular benefits.

Infection


Recent evidence has suggested the role of sexually transmitted infections as one of the causative factors for prostate cancer. People who have had sexually transmitted infections are reported as having 1.4 times greater chance of developing the disease compared to the general population.

Cadmium


Exposure to chemicals such as cadmium may be implicated in the development of prostate cancer.

Selenium and vitamin E


While initial reports of the Selenium and Vitamin E Cancer Prevention Trial,  found no reduction in risk of prostate cancer with either selenium or vitamin E supplements, recent conclusions confirmed that vitamin E not only fails to prevent prostate cancer but actually increases prostate cancer risk. In this study, men who took vitamin E supplement 400 IU per day had a 17% increase in their risk of the disease. Therefore, patients should be advised not to take vitamin E supplement.


Recognizing Prostate Cancer Symptoms


Early prostate cancer often does not cause symptoms. But prostate cancer can cause any of these problems:

  • A need to urinate frequently, especially at night;
  • Difficulty starting urination or holding back urine;
  • Inability to urinate;
  • Weak or interrupted flow of urine;
  • Painful or burning urination;
  • Difficulty in having an erection;
  • Painful ejaculation;
  • Blood in urine or semen; or
  • Frequent pain or stiffness in the lower back, hips, or upper thighs.

Any of these symptoms may be caused by cancer or by other, less serious health problems, such as BPH or an infection. A man who has symptoms like these should see his doctor or a urologist (a doctor who specializes in treating diseases of the genitourinary system).

Call Your Doctor About Prostate Cancer If:


  • You have trouble urinating or find that urination is painful or different from normal; your doctor should examine your prostate gland to determine whether it is enlarged, inflamed with an infection, or cancerous.
  • You have chronic pain in your lower back, pelvis, upper thighbones, or other bones. Pain in these areas can be caused by different things, including the spread of prostate cancer.
  • You have unexplained weight loss.
  • You have swelling in your legs.
  • You have weakness in your legs or difficulty walking, especially if you also have constipation.

How is prostate cancer diagnosed?


Your GP will ask about your symptoms and examine you. He or she may do some of the following tests, or refer you to a urologist (a doctor who specialises in identifying and treating conditions of the urinary system).

  • A blood test to measure the amount of PSA in your blood. PSA is a protein that is made by both normal and cancerous prostate cells. The test can be unreliable as a high PSA level doesn't always mean that you have cancer – it can be caused by other prostate conditions.
  • A digital rectal examination (DRE) – an examination of your prostate. Your doctor will feel your prostate through the wall of your rectum (back passage). If you have prostate cancer, it may feel harder than usual, or knobbly.
  • A prostate biopsy. A biopsy is a small sample of tissue. This will be sent to a laboratory for testing to determine the type of cells and if these are benign or cancerous.
  • An ultrasound to examine your prostate gland, using a small device inserted into your rectum.
  • CT scan, MRI scan and bone scans can help your surgeon see how far the cancer has spread (if at all).

Assessing the severity and spread of prostate cancer


The severity of the disease is mainly based on three factors - the grade of the cancer cells, the stage of the cancer, and the blood PSA level.

Grade of the cancer


Biopsy samples are looked at under the microscope to asses the cancer cells. By looking at certain features of the cells, the cancer can be graded. The common grading system used is called the Gleason Score.

A Gleason score of between 2 and 6 is a low-grade prostate cancer. It is likely to grow very slowly. A Gleason score of 7 is an intermediate grade that will grow at a moderate rate. A Gleason score of 8 to10 is a high-grade cancer that is likely to grow more quickly.

Staging


If you are confirmed to have prostate cancer, further tests may be advised to assess if it has spread. These tests are not advised in all cases. It depends on factors such as your age and the grade of the tumour cells. Tests which may be done include a bone scan, a CT scan, an MRI scan, an abdominal ultrasound scan or other tests. See separate leaflets called 'Bone Scan', 'CT Scan', 'MRI Scan' and 'Ultrasound Scan' for details of these tests. This assessment is called staging of the cancer. The aim of staging is to find out:

  • How much the tumour has grown, and whether it has grown through the wall of the prostate and into nearby structures such as the bladder wall.
  • Whether the cancer has spread to local lymph nodes.
  • Whether the cancer has spread to other areas of the body (metastasised).

Preparing for Prostate Cancer Treatment


The doctor develops a treatment plan to fit each man's needs. Treatment for prostate cancer depends on the stage of the disease and the grade of the tumor (which indicates how abnormal the cells look, and how likely they are to grow or spread). Other important factors in planning prostate cancer treatment are the man's age and general health and his feelings about the treatments and their possible side effects.

Many men with prostate cancer want to learn all they can about their disease, their treatment choices, and the possible side effects of treatment, so they can take an active part in decisions about their medical care. Prostate cancer can be managed in a number of ways (with watchful waiting, surgery, radiation therapy, and hormonal therapy). If the doctor recommends watchful waiting, the man's health will be monitored closely, and he will be treated only if prostate cancer symptoms occur or worsen. Patients considering surgery, radiation therapy, or hormonal therapy may want to consult doctors who specialize in these prostate cancer treatments.

The patient and his doctor may want to consider both the benefits and possible side effects of each option, especially the effects on sexual activity and urination, and other concerns about quality of life.

These are some questions a patient may want to ask the doctor before treatment begins:

  • What is the stage of the disease?
  • What is the grade of the disease?
  • What are my treatment choices? Is watchful waiting a good choice for me?
  • Are new treatments under study? Would a clinical trial be appropriate for me?
  • What are the expected benefits of each kind of treatment?
  • What are the risks and possible side effects of each treatment? How can the side effects be managed?
  • Is treatment likely to affect my sex life?
  • Am I likely to have urinary problems?
  • Am I likely to have bowel problems, such as diarrhea or rectal bleeding?
  • Will I need to change my normal activities? If so, for how long?

What are the treatment options for prostate cancer?


The treatment of prostate cancer is complicated. It varies tremendously between different cases. In addition, different men may choose to have different treatments compared to others with a similar type of prostate cancer.

Treatment options which may be considered include: surgery, radiotherapy, hormone treatment and, less commonly, chemotherapy. Often a combination of two or more of these treatments is used. The treatments used depend on:

  • the cancer itself - its size and stage (whether it has spread), the grade of the cancer cells, the PSA level; 
  • the man with the cancer - your age, your general health and also personal preferences for treatment.
For example, certain types of prostate cancer are confined to the prostate, are slow-growing and are unlikely to affect your life expectancy. Some types are more aggressive, more likely to spread and may cause serious illness and lead to death unless treated. The risks and possible side-effects of treatment are another consideration.

The treatment options are usually different for early prostate cancer that is confined to the prostate gland, local advanced prostate cancer, and late or advanced prostate cancer.

You should have a full discussion with a specialist who knows your case. They will be able to give the pros and cons, likely success rate, possible side-effects, and other details about the various possible treatment options for your type of cancer. 

You should also discuss with your specialist the aims of treatment. For example:

  • Treatment may aim to cure the cancer. In particular, the earlier the stage of the cancer, the better the chance of a cure. (Doctors tend to use the word remission rather than the word cured. Remission means there is no evidence of cancer following treatment. If you are in remission, you may be cured. However, in some cases a cancer returns months or years later. This is why doctors are sometimes reluctant to use the word cured.)
  • Treatment may aim to control the cancer. If a cure is not realistic, with treatment it is often possible to limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.
  • Treatment may aim to ease symptoms. Even if a cure is not possible, treatments may be used to reduce the size of a cancer, which may ease symptoms such as pain. If a cancer is advanced then you may require treatments such as nutritional supplements, painkillers, or other techniques to help keep you free of pain or other symptoms.
The following is an overview of treatment options which you may have after discussion with your doctor.

Treatment options for early prostate cancer


Active surveillance


Many prostate cancers are diagnosed at an early stage by PSA testing. Prostate cancer is often very slow-growing and, for many men with prostate cancer, the disease may never progress or cause any symptoms. In other words, many men with prostate cancer will never need any treatment. Treatments for prostate cancer can cause side-effects, which can affect your lifestyle. By monitoring the cancer with active surveillance, you can avoid or delay the side-effects of treatment.

Active surveillance aims to find those cancers that are likely to grow and cause symptoms if they are not treated. These cancers can then be treated at an early stage. 

Active surveillance may be suitable if you have low- to medium-risk prostate cancer. It will involve regular check-ups with PSA tests, rectal examination of the prostate and possibly repeat prostate biopsies.

Surgery


Removing the prostate (radical prostatectomy) can be curative if the cancer is in an early stage (confined to the prostate and not spread). It is a major operation and so tends to be advised more often for younger men whose general health is good, especially if the cancer grade means the cancer is likely to spread in the future. Side-effects such as impotence and/or incontinence of urine may occur following a prostatectomy.

Radiotherapy


Radiotherapy is a treatment which uses high-energy beams of radiation which are focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying. See separate leaflet called 'Radiotherapy' for more details.

Radical radiotherapy may be used as an alternative to surgery. Two types of radiotherapy are used for prostate cancer - external and internal. Again, the type chosen depends on various factors such as the size, grade and stage of cancer. 

Radiotherapy is often more suitable for men who are not fit enough to have an operation or choose not to have an operation.

  • External radiotherapy. This is where radiation is targeted on the prostate cancer from a machine. (This is a common type of radiotherapy used for many types of cancer.)
  • Internal radiotherapy (brachytherapy). This treatment involves inserting a small radioactive implant into the cancerous tumour, or next to the tumour. Sometimes radioactive seeds are placed into the prostate gland. The seeds are left in place permanently but lose their radioactivity over time. Sometimes a larger radioactive implant is inserted into the prostate for a short time and then removed. External radiotherapy may be also given with this type of brachytherapy.

Treatment options for locally advanced prostate cancer


When the cancer has spread into the capsule of the prostate or into the surrounding tissues near to the prostate then it is called locally advanced prostate cancer.

You may be offered hormone treatment with radiotherapy. The radiotherapy given is usually similar to that given for men with early prostate cancer although the radiotherapy may include the surrounding structures in addition to the prostate. Some men just receive hormone treatment. As the choice of treatment depends on many factors, your doctor will discuss the treatment with you in more detail.

Hormone treatment


Prostate cancer cells need the male hormone called testosterone to grow and multiply well. Testosterone is made in the testes and circulates in the bloodstream. Hormone treatments aim to stop you from making testosterone or to block the effect of testosterone on prostate cancer cells. Hormone treatments do not cure prostate cancer but may greatly slow down the growth of the cancer for a number of years. 

Two groups of medicines are available:

  • Medicines which work on the pituitary gland. For example: goserelin and leuprorelin. (Your pituitary gland makes a hormone which circulates in the bloodstream to stimulate the testes to make testosterone. These medicines stop your pituitary from making this stimulating hormone.) These medicines are given by an injection.
  • Medicines which block the action of testosterone (anti-androgen medicines). For example: flutamide and cyproterone acetate. These medicines are tablets.
Hormone treatments can cause side-effects such as erectile dysfunction (impotence), hot flushes, sweating and other problems.

Treatment options for late or advanced prostate cancer


Late or advanced prostate cancer is when the cancer has spread to other parts of the body. Hormone treatments are usually given, as the cancer cells in other parts of the body still need testosterone to grow and multiply.

Another type of hormone treatment which may be offered is surgical removal of the testes (orchidectomy). Without testes you no longer make testosterone.

You may decide not to start hormone treatment until you develop symptoms. Your doctor will be able to discuss the timings of treatments with you in more detail.

Chemotherapy


Chemotherapy is a treatment of cancer by using anti-cancer medicines which kill cancer cells, or stop them from multiplying. See separate leaflet called 'Chemotherapy' for more details. Chemotherapy is not commonly used for the treatment of prostate cancer. It may be used for more advanced cancers.

Radiotherapy


Even if the cancer is advanced and a cure is not possible, radiotherapy may have a place to ease symptoms. For example, radiotherapy may be used to shrink secondary tumours which have spread to bones and are causing pain. Brachytherapy (a form of radiotherapy in which radiation is targeted directly at the prostate gland) in combination with external-beam radiotherapy is a treatment option for localised prostate cancer.

Watchful waiting


In some cases it may be best not to have any active treatment but to see how the cancer develops. This is called watchful waiting. Various factors are taken into account such as the stage of the cancer, your age, general health, the impact and the potential side-effects if treatment were to be used. Watchful waiting may be more appropriate for men where the cancer is not causing much in the way of symptoms, and is slow-growing, especially in older men. With a watchful waiting approach you will still have regular check-ups and the decision about treatment can be reviewed at any time.


Prevention of prostate cancer


Several studies are under way to explore how prostate cancer might be prevented. These include the use of dietary supplements. In addition, recent studies suggest that a diet that regularly includes tomato-based foods may help protect men from prostate cancer.

The drug finasteride is being studied in the Prostate Cancer Prevention Trial, which involves thousands of men across the country who are participating for 7 years, until 2004.

Scientists are also looking at ways to prevent recurrence among men who have been treated for prostate cancer. These approaches involve the use of drugs such as finasteride, flutamide, and LH-RH agonists. Studies have shown that hormonal therapy after radiation therapy or after radical prostatectomy can benefit certain men whose cancer has spread to nearby tissues.

Stopping smoking.

Researchers also are investigating whether diets that are low in fat and high in soy, fruits, vegetables, and other food products might prevent a recurrence. The Cancer Information Service can provide information about these studies.

Support for Men with Prostate Cancer


Living with a serious disease such as cancer is not easy. Some people find they need help coping with the emotional as well as the practical aspects of their disease. Patients often get together in support groups, where they can share what they have learned about coping with their disease and the effects of prostate cancer treatment. Patients may want to talk with a member of their health care team about finding a support group.

People living with cancer may worry about caring for their families, keeping their jobs, or continuing daily activities. Concerns about prostate cancer treatments and managing side effects, hospital stays, and medical bills are also common. Doctors, nurses, dietitians and other members of the health care team can answer questions about treatment, working, or other activities. Meeting with a social worker, counselor, or member of the clergy can be helpful to those who want to talk about their feelings or discuss their concerns. Often, a social worker can suggest resources for help with rehabilitation, emotional support, financial aid, transportation, or home care.

It is natural for a man and his partner to be concerned about the effects of prostate cancer and its treatment on their sexual relationship. They may want to talk with the doctor about possible side effects and whether these are likely to be temporary or permanent. Whatever the outlook, it is usually helpful for patients and their partners to talk about their concerns and help one another find ways to be intimate during and after treatment.